Why are roofs on new builds made out of wood and not steel?

GreeBo

Lumen wrote: »

I'm not sure why more gabled houses don't use a steel ridge beam (and steel king posts,, if the house is otherwise timber framed), plus external (to the load bearing structure) roof insulation.

It solves the wall spreading issue without the need for ties, so had the potential to great incredible vaulted spaces, keep MHRV services inside the envelope etc.

I was in a rented house in Stepaside for a few months, A rated and built probably in the last 5 years and it had a mixture of steel beams and timber in the attic. It was a cold space though and not really vaulted, so not sure why, but to be fair I didnt really investigate.

maestroamado

GreeBo wrote: »

I was in a rented house in Stepaside for a few months, A rated and built probably in the last 5 years and it had a mixture of steel beams and timber in the attic. It was a cold space though and not really vaulted, so not sure why, but to be fair I didnt really investigate.

In recent years there is steel beam going from gable to gable.
It used be 9"x3" wood but it seems to have changed.
I assume the reason its cold it well isulated so heat stays in the house....

v638sg7k1a92bx

Mellor wrote: »

Not really.
A prefab timber truss goes straight up, so does a prefab steel truss.
If you have to chop and change either, then you have messed up somewhere.

Obvious a timber cut roof is cut and measured on site. But so too would a steel cut roof be. You have to compare like with like.

When I was in Oz an NZ we worked on refurbs and renovations and it was always a steel roof cut and measured offsite and lifted in by a crane - no cutting, copping, changing but In Ireland we seem to complicate the whole issue, "oh we don't do it that way over here" "timber is just as good" "that wouldn't work over here"

Lumen

Anaya Sticky Self-portrait wrote: »

When I was in Oz an NZ we worked on refurbs and renovations and it was always a steel roof cut and measured offsite and lifted in by a crane - no cutting, copping, changing but In Ireland we seem to complicate the whole issue, "oh we don't do it that way over here" "timber is just as good" "that wouldn't work over here"

NZ has earthquakes. I've no idea whether that explains the difference, but I wouldn't assume that we are doing it wrong just because we are doing it differently.

Americans talk about "20 and 30 year roofs". For them the roof is almost a consumable part. Is that wrong? I don't know. Presumably it works for them.

Mellor

Anaya Sticky Self-portrait wrote: »

When I was in Oz an NZ we worked on refurbs and renovations and it was always a steel roof cut and measured offsite and lifted in by a crane - no cutting, copping, changing but In Ireland we seem to complicate the whole issue, "oh we don't do it that way over here" "timber is just as good" "that wouldn't work over here"

If it’s constructed off-site and lifted in by crane it’s a prefab truss not a cut roof. You are getting two different things mixed up.
A preference for steel in NZ is possibly driven by earthquakes.

In Australia, both steel and timber prefab trusses are used, but timber cut roofs are by far the most common. Timber framed houses are, in general, more common than in Ireland. They wouldn’t use brick/block cavity as much.

Steel studs are more common in commercial scale steel/concrete framed buildings however.

v638sg7k1a92bx

Mellor wrote: »

If it’s constructed off-site and lifted in by crane it’s a prefab truss not a cut roof. You are getting two different things mixed up.
A preference for steel in NZ is possibly driven by earthquakes.

In Australia, both steel and timber prefab trusses are used, but timber cut roofs are by far the most common. Timber framed houses are, in general, more common than in Ireland. They wouldn’t use brick/block cavity as much.

Steel studs are more common in commercial scale steel/concrete framed buildings however.

Don’t get me started on the studs. I can’t understand how steel studs are not standard in all buildings. When I would see timber studs going into buildings my stomach would drop.

GreeBo

Anaya Sticky Self-portrait wrote: »

Don’t get me started on the studs. I can’t understand how steel studs are not standard in all buildings. When I would see timber studs going into buildings my stomach would drop.

When i see steel studs going in I'm more worried that my flat screen tv will drop.

GreeBo

Lumen wrote: »

NZ has earthquakes. I've no idea whether that explains the difference, but I wouldn't assume that we are doing it wrong just because we are doing it differently.

Americans talk about "20 and 30 year roofs". For them the roof is almost a consumable part. Is that wrong? I don't know. Presumably it works for them.

Yeah, the US has a huge industry around re-roofing, but I thought that was typically around the shingle side of things and maybe the sheathing if the last guy botched the shingles but that it wasnt at all about the roof structure itself.

v638sg7k1a92bx

GreeBo wrote: »

When i see steel studs going in I'm more worried that my flat screen tv will drop.

First world problems there Bo, you need to check your privilege.

Mellor

maestroamado wrote: »

The design of trusses means they cannot be chopped as the strength is in the design to spread the weight directly downward on walls.

I missed this one yesterday. I haven't suggested trusses work any other way.

Anaya Sticky Self-portrait wrote: »

Don’t get me started on the studs. I can’t understand how steel studs are not standard in all buildings. When I would see timber studs going into buildings my stomach would drop.

I'm a big fan of steel studs for commercial construction. Fast, strong and very good acoustically. However they don't handle twisting, or offset loads as well. So less future adaptable in residential.

GreeBo wrote: »

When i see steel studs going in I'm more worried that my flat screen tv will drop.

TVs are getting lighter. By current TV is supported on a steel furring channel and plasterboard lining without issued. But the bracket is very good.

Heavier TVS are fine as long as you know in advance where that are going, and the wall is braced.

GreeBo

Mellor wrote: »

TVs are getting lighter. By current TV is supported on a steel furring channel and plasterboard lining without issued. But the bracket is very good.

Heavier TVS are fine as long as you know in advance where that are going, and the wall is braced.

Yeah but that is kinda the point. Who knows what will go where in 5 years time.
Right now you find a stud and stop worrying, with metal studs it's not so simple.

100% agree that they have their uses, typically commercial where the wall can be short-lived and there is control over the loads placed on the wall.

Mellor

GreeBo wrote: »

Yeah but that is kinda the point. Who knows what will go where in 5 years time.
Right now you find a stud and stop worrying, with metal studs it's not so simple.

I get that completely, but it’s down to the right fixings not timber vrs steel.
As I said, I’ve a TV, 60” hung off plasterboard and fittings with the right fixing.
And i’ve seen bigger without issue.

The main concern is the kitchen units and the sex swing

Yellow_Fern

It is worth pointing out that the use of steel is creeping in. from factory assembled trusses to RSJs on gables and easi joists steel is increasingly being used for roofs and floors.

v638sg7k1a92bx

Yellow_Fern wrote: »

It is worth pointing out that the use of steel is creeping in. from factory assembled trusses to RSJs on gables and easi joists steel is increasingly being used for roofs and floors.

That's what I'm saying. In Ireland we latch onto certain ways of doing things e.g. carpets and saddle boards :pac:

Seriously, the main reason is probably because steel is not that much more expensive than timber these days.

theguzman

Timber is good for nothing here in my own opinion it rots far too easily and Ireland has one of the worst miserable climates you can imagine for timber. The softwood crap that they plant here isn't worth a damn, fences and patio decking done during the boom have mainly rotted away now. Farmers on an never-ending journey of fencing with softwood stakes. Oak; the Brown oak is the only wood of any use I would use in structural timber because I am thinking longevity. More Concrete builds and Steel roofs should be encouraged I would say. Irish White Deal Spruce would be perfect for places like Dubai or Saudi Arabia where they are bone dry all the time but not Ireland.

ted1

Anaya Sticky Self-portrait wrote: »

Is it purely down to cost? Seems that steel is so much more sturdy than wood and that roofs are prone to problems why are roofs on new builds not made out of steel?
New houses being built on our road and the roof is al made out of timber.

Wood would be just as sturdy and copes with fire better

ted1

Anaya Sticky Self-portrait wrote: »

Don’t get me started on the studs. I can’t understand how steel studs are not standard in all buildings. When I would see timber studs going into buildings my stomach would drop.

Easier to hang a tv off a wooden stud.

awec

Metal studs are a pain in the arse.

Yellow_Fern

theguzman wrote: »

Timber is good for nothing here in my own opinion it rots far too easily and Ireland has one of the worst miserable climates you can imagine for timber. The softwood crap that they plant here isn't worth a damn, fences and patio decking done during the boom have mainly rotted away now. Farmers on an never-ending journey of fencing with softwood stakes. Oak; the Brown oak is the only wood of any use I would use in structural timber because I am thinking longevity. More Concrete builds and Steel roofs should be encouraged I would say. Irish White Deal Spruce would be perfect for places like Dubai or Saudi Arabia where they are bone dry all the time but not Ireland.

Metal is creeping in to house construction but it has its own problems. Metal is highly conductive and its easy to interupt your thermal envolpe because of this. One remarkably counter intutive but supposedly very effective way to preserve wood is to burn it. Charr the surface and it stops it rotting. Shou sugi ban, check it out.

Mellor

awec wrote: »

Metal studs are a pain in the arse.

They are significantly better on big jobs. For speed, services, and numberous other reasons.
The issue is that have to be detailed properly, and installed properly, neither of which is particularly strong in Ireland. Maybe it's getting better, but in the past they weren;t even mentioning building design/architectural courses. Instead it was all Homebond guide.

GreeBo

Mellor wrote: »

They are significantly better on big jobs. For speed, services, and numberous other reasons.
The issue is that have to be detailed properly, and installed properly, neither of which is particularly strong in Ireland. Maybe it's getting better, but in the past they weren;t even mentioning building design/architectural courses. Instead it was all Homebond guide.

I'd prefer my house construction to be "better" for it's useful life rather than during its construction.

Lumen

theguzman wrote: »

Timber is good for nothing here in my own opinion it rots far too easily and Ireland has one of the worst miserable climates you can imagine for timber. The softwood crap that they plant here isn't worth a damn, fences and patio decking done during the boom have mainly rotted away now. Farmers on an never-ending journey of fencing with softwood stakes. Oak; the Brown oak is the only wood of any use I would use in structural timber because I am thinking longevity. More Concrete builds and Steel roofs should be encouraged I would say. Irish White Deal Spruce would be perfect for places like Dubai or Saudi Arabia where they are bone dry all the time but not Ireland.

There is a world of difference between a fence post and a rafter. They're completely different applications.

In a modern externally insulated roof the structural timbers don't even get cold, let alone wet.

Mellor

GreeBo wrote: »

I'd prefer my house construction to be "better" for it's useful life rather than during its construction.

None of the issues I mentioned were construction benefits. That's the contractors area of concern.

Speed, might seem like a construction issue. But it's actually a budget one. Building more faster reduces cost for the client/owner.
Services benefit should be a no brainer. Much easier to reticulate increased amount of services that you find in commercial jobs.
Also much easier to dismount and reconfigure over time. Which has obvious commercial benefits for a client.

On the scale of a one off house, might not be of interest. As I said, on big jobs. Even the biggest house, is a very small job.

GreeBo

Lumen wrote: »

There is a world of difference between a fence post and a rafter. They're completely different applications.

In a modern externally insulated roof the structural timbers don't even get cold, let alone wet.

If your rafters are getting wet you should confirm that you have them on the right side of the tiles!

circadian

theguzman wrote: »

Timber is good for nothing here in my own opinion it rots far too easily and Ireland has one of the worst miserable climates you can imagine for timber. The softwood crap that they plant here isn't worth a damn, fences and patio decking done during the boom have mainly rotted away now. Farmers on an never-ending journey of fencing with softwood stakes. Oak; the Brown oak is the only wood of any use I would use in structural timber because I am thinking longevity. More Concrete builds and Steel roofs should be encouraged I would say. Irish White Deal Spruce would be perfect for places like Dubai or Saudi Arabia where they are bone dry all the time but not Ireland.

Timber is good for nothing? It's great if maintained. It rains more in the Pacific Northwest and they build their homes with timber frames and wooden facades. No brickwork there and those houses are fine.

booooonzo

theguzman wrote: »

Timber is good for nothing here in my own opinion it rots far too easily and Ireland has one of the worst miserable climates you can imagine for timber. The softwood crap that they plant here isn't worth a damn, fences and patio decking done during the boom have mainly rotted away now. Farmers on an never-ending journey of fencing with softwood stakes. Oak; the Brown oak is the only wood of any use I would use in structural timber because I am thinking longevity. More Concrete builds and Steel roofs should be encouraged I would say. Irish White Deal Spruce would be perfect for places like Dubai or Saudi Arabia where they are bone dry all the time but not Ireland.

This is the classic outdated, old school response with not much thinking behind it.... although i agree the crap they plant is useless and very damaging environmentally